KR100978988B1 - Multiple outlet rolling mill - Google Patents

Abstract

The accumulator is sandwiched between an initial mill section having an elevated first production rate and a plurality of different outlet mill sections each having a lower second production rate. Each accumulator is configured to receive the intermediate product from the initial mill section at the elevated first production rate of the initial mill section and to transfer the intermediate product to the associated exit mill section at each lower second production rate of the associated exit mill section. And arranged. The excess intermediate product resulting from the difference between the first and second production rates is temporarily stored in the accumulator. The switch guides the successive intermediate product lengths from the initial mill section to the selected outlet mill section through each accumulator of the outlet mill section selected for simultaneous treatment with the packaged finish product.

Rolling Mills, Initial Rolling Mill Sections, Outlet Rolling Mill Sections, Accumulators, Switching Means

Description

Multi Exit Rolling Mill {MULTIPLE OUTLET ROLLING MILL}

The present invention relates to a continuous hot rolling mill of the type designed to produce long products as a whole.

Conventional mills designed to produce long articles typically include an initial mill section comprising a furnace for reheating the billet, roughing and rolling the heated billet into an intermediate article having a reduced cross-sectional area and The intermediate mill section follows the initial mill section. Differently configured outlet mill sections are then selectively and individually employed to further roll the intermediate product into a finished product which is packaged according to the customer's requirements.

The initial mill section in most cases has an increased "first" production rate that exceeds the lower "second" production rate of the individual outlet mill section. Thus, in most of the finish products of rolling mills, the higher first production rate of the initial rolling mill section cannot be realized because the whole rolling mill must be slowed down to meet the lower production rate of the exit rolling mill section currently in use. The final reduced production rate is a significant loss for mill operators when combined with capital investment (called “dead money”) for exit mill sections that are not currently used.

It is an object of the present invention to simultaneously operate different multiple mill exit sections with combined production rates that exceed the second production rate of the individual outlet sections and are ideally the same to maximize the increased first production rate of the initial mill section. It is to provide a means for making it.

According to the invention, an accumulator is interposed between the initial mill section and each outlet mill section. Each accumulator receives intermediate products from the initial mill section at an increased first production rate of the initial mill section and transfers the intermediate products to the associated exit mill section at each lower second production rate of the associated exit mill section. Are constructed and arranged. The excess intermediate product resulting from the difference between the first and second production rates is temporarily stored in the accumulator. The switch guides the successive intermediate product lengths from the initial mill section to the selected outlet mill section through each accumulator of the outlet mill section selected for simultaneous treatment with the packaged finish product.

Objects associated with the above objects, and further advantages will now be described with reference to the accompanying drawings.

According to the invention, simultaneously operating different multiple mill exit sections with a combined production rate that exceeds the second production rate of the individual outlet sections and ideally becomes the same to maximize the increased first production rate of the initial mill section. It may provide a means for making it.

As shown in FIG. 3, a conventional rolling mill configured to roll long articles will include a furnace 10 for reheating billets received from the yard 12. A typical billet 13 will have a rectangular cross section measuring 130x130 to 250x250mm, a length of 5 to 14m and a weight of about 1,500 to 4,000kg. The reheated billet is rolled in a series of roughing and intermediate rolling stands (collectively indicated by reference numeral 14) to produce an intermediate product 16, such as a circular body having a diameter of 20 to 35 mm. The furnace 10 and roughing and intermediate rolling stand 14 include an initial mill section "IMS" (Initial Mill Section) that will have a relatively high first production rate, typically on the order of 150 to 360 tons per hour. do.

The switch 18 serves to selectively guide the intermediate product to one of several outlet mill sections OMS ₁ , OMS ₂ , OMS ₃ . The outlet mill section OMS ₁ is a processing line with a prefinishing roll stand 20 for rolling the intermediate product 16 into a circular body 22 having a reduced diameter of 16 to 28 mm, and 5 to 22 mm. It has a finishing block 24 for producing a finished product 26 having a diameter of. Finishing product 26 is then subjected to further processing, including shaping to ring 28 by a laying head 30, which ring is to the reshaping chamber 34 where the ring is collected into an upright coil. It is housed in a Spencerian form on a cooling conveyor 32 for transporting it. The outlet mill section OMS ₁ will normally be operated at a maximum second production rate of about 70 to 150 tons / hour.

The outlet mill section OMS ₂ carries a pre-finish roll stand 20 which rolls the intermediate product into so-called "dog bone" sections which are subsequently cut into circular bodies 38 having a reduced diameter of 16 to 28 mm. It has the processing line to include and the two finishing blocks 24 which roll the circular body 38 with the same 8.0 mm finished product 26. As shown in FIG. These finished products 26 are guided to a cooling table 40 where the length of the finished product is cooled before it is collected and strapped into bundles at a bundling station 42. The outlet mill section OMS ₂ will normally be operated at a maximum second production rate of 25 to 150 tonnes / hour.

The exit mill section OMS ₃ comprises a processing line with a pre-finish roll stand 20 and a finishing block 24. Here, the finished product, which is again 8.0 mm circular body 26, is guided to a switch 44 which alternately supplies two spoolers 46a, 46b. The maximum second production rate of the outlet mill section OMS ₃ is also 25 to 150 tons / hour.

In this conventional mill layout, the outlet mill sections OMS ₁ , OMS ₂ , OMS ₃ must be operated individually at each second production rate of the outlet mill section, but cannot be operated simultaneously. Thus, if the initial mill section has a production rate of, for example, 300 tonnes / hour and the switch 18 is set to direct the intermediate product length to the outlet mill section OMS ₁ , the whole mill is subjected to the second part of the outlet mill section. While slowing in tuning, the other outlet mill sections OMS ₂ , OMS ₃ remain idle. Using one or the other of the exit mill sections OMS ₂ , OMS ₃ will also result in a reduction to the production rate of the mill below the maximum of the initial mill section.

According to one embodiment of the invention, the initial mill section IMS is basically unchanged as shown in FIG. The exit mill section OMS ₃ is reconfigured in a state in which the pre-finish roll stand 20 for producing the dogbone section is cut into circular bodies and supplied to the two finishing blocks 24. The finished product is then directed to a switch 44 which alternately supplies a pair of spoolers 46a and 46b. An accumulator 48 is installed in front of each outlet mill section. Accumulators are preferably of the type described in US Pat. No. 7,021,103, the disclosure of which is incorporated herein by reference.

Each accumulator 48 is constructed and arranged to receive the intermediate product at the production rate of the initial mill section IMS and to simultaneously transfer the intermediate product to the associated outlet mill section at a reduced production rate of the initial mill section. Excess intermediate products resulting from the manufacturing rate are temporarily stored in the accumulator.

For example, in the mill layout shown in FIG. 1, the initial mill section IMS has a production rate of 275 tons / hour, and the outlet mill sections OMS ₁ , OMS ₂ , OMS ₃ are 75, 100 and 100 tons, respectively. Assume that it has a production rate of / hour. Referring to FIG. 4A, a typical rolling sequence will begin with the intermediate product length being guided to the accumulator 48 of the outlet mill section OMS ₁ . The intermediate product is received at the first production rate of the initial mill section of 275 tons / hour and simultaneously distributed from the accumulator to the processing line at the production rate of the exit mill section of 75 tons / hour. The difference that arises due to different production rates is temporarily stored on the accumulator. Full intermediate product length portion being received in the last accumulator in the time interval (t _1), is at the end of the time interval (t ₂₎ completely processed by the outlet mill sections (OMS _1).

As soon as all of the intermediate product lengths are received on the accumulators of OMS ₁ , the next product lengths are guided to the accumulators of OMS ₂ . This stepwise process continues to OMS ₃ . Until the accumulator of OMS ₃ has received all of the intermediate product lengths, the accumulator of OMS ₁ is empty and ready to receive the next product length. As such, it will be appreciated that by sequentially employing the multiple exit mill sections enabled by the interposition of the accumulator 48, the mill can be operated continuously at the maximum production rate of the mill of 275 tons / hour.

Figure 2 illustrates a mill layout similar to the outlet mill sections (OMS ₁ ') and, OMS _1' and OMS _1, any one of an optionally added to the switch 50 to supply, Figure 1 of. Here, the production rate of the initial mill section IMS is increased to 350 tons / hour.

4B shows a typical rolling sequence of the layout of FIG. Here again, the stepwise rolling sequence makes it possible to roll continuously at the maximum production rate of the initial mill section.

1 and 2 are schematic diagrams of exemplary mill layouts embodying the concepts of the present invention.

3 is a schematic diagram of an exemplary rolling mill layout according to a conventional implementation.

4A and 4B are time charts showing the rolling sequence for the mill layout shown in FIGS. 1 and 2;

<Explanation of symbols for the main parts of the drawings>

10: no

12: yard

13: billet

14: Roughing and Medium Rolling Stand

16: intermediate products

18, 44: switch

20: pre-finish roll stand

22: circular body

24: finishing block

26: finishing products

28: ring

30: laying head

32: cooling conveyor

34: reshaping chamber

46a, 46b: spooler

48: accumulator

IMS: Initial Rolling Mill Section

OMS ₁ , OMS ₂ , OMS ₃ Outlet mill section

Claims (2)

An initial mill section configured and arranged to reheat and continuously roll the billet to an intermediate product at a first rate of manufacture; A differently constructed multiple exit mill section configured and arranged to additionally roll the intermediate product into a finished product packaged at a second production rate less than the first production rate, the product being manufactured by at least a portion of the exit mill section The form of the package is different from that of the package produced by the other part of the outlet mill section; The intermediate product interposed between each of the outlet mill sections and the initial mill section, receiving the intermediate product at the first production rate, and at each second production rate of an associated exit mill section, with an associated outlet mill section. An accumulator each configured and arranged to convey an accumulator, the excess intermediate product resulting from the difference between the first and second production rates being accumulator temporarily stored within the accumulator; Receiving the continuous length of the intermediate product from the initial mill section and selectively guiding the intermediate product to the selected outlet mill section via each accumulator of the outlet mill section selected for simultaneous treatment of the intermediate product to the finished product. Rolling mill comprising switch means for. The rolling mill of claim 1, wherein the outlet mill section is operable simultaneously at a second production rate collectively equal to the first production rate.

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